Telegraph repeater system



1953 E. ROSSBERG ET AL 2,654,803

TELEGRAPH REPEATER SYSTEM Filed Oct. 7, 1950 2 Sheets-Sheet 1 a 1, l 2 bl Hg; Jive 0715.

fiwafisabery. K, ZZZ/65f; Jbafwz'm 2am Patented Oct. 6, 19 53 UNITED STATES PATENT OFFICE TELEGRAPH REPEATER SYSTEM Ehrhard Rossberg,

Berlin- Siemensstadt,

and

Application October 7, 1950, Serial No. 188,917 In Germany October 8, 1949 6 5 Claims.

This invention relates to telegraph repeater systems for telegraph printers operating in accordance with the start-stop principle, e. g., with a five-unit code, comprising a signal-receiving distributor and means for transmitting the distributed signals, and is particularly concerned with circuit means for controlling the operative release of the receiving distributor responsive to received signals.

Repeaters of this kind are employed when it is desired to correct signal distortions, or when signals are to be transmitted in predetermined time relationship over a multiple-purpose transmission channel. The receiving distributor comprises a rotatable cam shaft for actuating cams relative to associated contacts, a rotating drive shaft which is frictionally coupled with the cam shaft, e. g., by a slip clutch, detent means for holding the cam shaft in a normal position against rotation and a release magnet for actuating the detent. The release magnet is in a local circuit controlled by a contact governed by a line relay which is responsive to transmitted impulses received over a transmitting line. The release magnet is in a normal position when there is spacing or stop current on the line, and the detent controlled thereby holds the cam shaft against rotation. The line relay operates in response to marker current on the line, thereby causing the release magnet to energize (start signal), and the latter actuates the detent to release the cam shaft for one revolution. The five characteristic code signals are then received while the cam shaft rotates and are scanned by the cam-operated contacts for transmission and,

if desired, for storing purposes. Spacing current is again placed on the line at the end of the transmitted code, and the release magnet is deenergized to stop the rotation of the cam shaft by placing the detent in its normal position. The cycle is repeated by the receipt of the start impulse of the next following code. A system of this kind is disclosed, for example, in the U. S.

addition to the five-unit code signals, for example, in a case where prolonged marker current is transmitted to signify clearance or to indicate that there is no established connection. The contact controlled by the line relay will remain in its actuated position for the duration of this prolonged signal, and the release magnet (which controls the release detent for the cam shaft) will accordingly be i e-energized and will cause continued rotation of the cam shaft so long as the prolonged signal is on the line. Known systems therefore provide circuit means for by-passing the receiving distributor during the transmission of the prolonged signal so as to prevent the unnecessary rotation of the cam shaft.

The object of the invention is to provide circuit means for remedying this shortcoming. This object is realized by utilizing as a criterion for the operation of the release magnet the occurrence, that is, the instant of a change in the current condition on the transmission line, as contrasted with the prior systems in which this criterion is the current condition on the line as such.

Consequently, a prolonged current on the transmission linewhile it will hold the line relay in a predetermined positionwill not cause re-operation of the release magnet. Such magnet will be actuated to bring about the release of the cam shaft only at the instant when the current condition on the transmission line changes.

Generally speaking, this operative actuation of the release magnet may be brought about either upon change-over on the transmission line from spacing to marker current, or vice versa. Another object of the invention is to provide, in view of this alternate operating possibility, means for suppressing the release operation of the release magnet responsive to change-over of the current condition on the line in a certain direction, e. g., so that the release operation is effected only upon change-over on the line from spacing current to marker current.

It will be appreciated from the foregoing explanations that it is not a predetermined current condition on the transmission line, which governs the operative release of the receiving distributor, but always and exclusively the change-over from one to another current condition. The invention is realized by the provision of diiferentiating means for controlling the circuit of the release magnet in response to such change-over in the current conditions on the transmission line.

The differentiating means may in one embodiment be circuit means for the release control magnet, which causes energization thereof in the presence of either spacing or marker current on the line. The magnet will deenergize only at the instant when the current condition on the line changes. The detent coacting with the cam shaft will be brought into release position responsive to release of the magnet to release the shaft for one revolution. The stopping is effected at the end of such revolution, regardless of the particular position (marker or spacing) in which the line relay may be at the end of the transmission of the code. Only another change in the current condition on the line will cause another release operation.

Other embodiments provide condenser means in the circuit of the release magnet for producing by potential alteration, responsive to the change-over of the position of the contact of the line relay, charging and discharge currents which cause corresponding actuation of the release magnet. As in the former case, the stopping is effected at the end of a revolution of the cam shaft entirely independent of the position of the line relay (spacing or marker position) and consequently indepedent of the position of the contact controlled by the line relay which is in the local circuit of the release magnet.

Rectifier means may be provided in the embodiment noted in the preceding paragraph, for suppressing actuation of the release magnet responsive to change-over on the transmission line from one to the other current condition, e. g., change-over from marker to spacing current, while effecting its actuation responsive to change-over from spacing to marker current. The rectifier means may be in the form of a bridge circuit for causing the charging current from the condenser to flow through the winding of the release magnet always in a predetermined direction.

The differentiating means may also be in the form of a transformer having its primary winding in circuit with the contact controlled by the line relay and, its secondary Winding in parallel with the winding of the release magnet. Accordingly, there will be energizing current on the secondary winding for the actuation of the release magnet only responsive to change of polarity in the primary circuit of the transformer.

In accordance with another feature, an electron discharge tube may be employed in circuit with the release magnet and having a bias, circuit for its grid which becomes effective only responsive to change-over of the current condition on the transmission line.

Examples of embodiments of the invention will now be described with reference to the accompanying drawings. In these drawings,

Fig. 1 illustrates in schematic manner an arrangement which is suitable for repeating and correcting the distortion of start-stop signals having a prolonged stop impulse;

Fig. 2 shows in similar diagrammatic manner an arrangement for repeating by a synchronizing means in a predetermined time-sequence} start-stop signals which are received in irregular sequence;

Figs. 3 and 4 indicate embodiments of means for controlling the operative release of the receiving distributor by condenser means and by transformer means, respectively;

Fig. 5 indicates an example of means for effecting the release of the signal-receiving distributor only upon change-over in the transmis sion line from spacing to marker current;

Fig. 6 represents circuit means for affecting the release control magnet but causing the. ourrent to flow through its winding only in a certain direction; and

Fig. '7 shows a circuit similar to Fig. 6, but utilizing a discharge tube.

Known details or elements or such as may be derived from the disclosure have been omitted in the drawings in order to keep them simple and lucid.

Referring now to Fig. l, we will first describe a repeater circuit in which prolonged stop signals may be transmitted. The input end of the circuit is formed by the receiver relay E which is connected with the transmission line on and In. In the normal position, the armature e of this relay connects with the left hand contact and thus with the positive current source +TB. One side of the release control magnet A is operatively connected to a central battery point relative to +TB and TB, which in the drawings is illustrated as at ground, whereby the magnet A will be energized when relay armature e is connected to either +TB or 'TB, thus maintaining the magnet armature in its attracted position irrespective of the polarity of the connections to the magnet and releasing the magnet armature only when a current alteration takes place. In other words, the arrangement is such that release is effected, not by a condition resulting from a change in the received current, but by the transition from one condition to the other. Such transition in relation to time thus may be expressed as current differentiation and the means for achieving the desired results as the current differentiating means; The armature forms a detent for the pawl K. If the incoming current is varied, the armature e will connect with its right hand contact and therewith with the negative current source TB. The current passes through 0 at the transition from to The magnet A releases its armature (detent) at.

this moment and thereby frees the pawl K. The cam shaft which is rotated by a motor (not shown) and which carries this pawl and also the cam disks Ni to N5 (shown in the drawing in developed view) is thus released for operation. Shortly after beginning its rotation the cam disk N1 closes its associated contact. The first code impulse is now absorbed and is simultaneously transmitted to the transmitter relay S. The latter transmits the impulse over the line (12 and be by means of its armature s. The successive code impulses are similarly scanned and transmitted by the actuation of the cam vantageously used in case trouble may be ex-- pected in the transmission channel, e. g., in the case of wireless transmission. The input is formed by the receiver relay E. Its armature e again transmits the signals'to the release control magnet A which releases the pawl K upon its deenergization. The scanning of the first code signal takes place shortly thereafter by means of the contact controlled by the cam disk N1.

The condenser G1 which is in circuit with this contact is'charged in accordance with the cork tact actuation. The condensers C2 to C5 are successively charged in similar manner by the actuation of associated contacts controlled by the respective cam disks NZ to N5. The cam dlSk F closes, shortly after the start of the revolution of the receiving distributor shaft, is coact ing contact and thereby prepares for the operative release of the transmitter haft. The latter, however, is operatively released only after closure of the contacts of the synchronous control device T. The release control magnet B of the transmitter shaft receives current at that moment and upon energizing releases the pawl L. The charged condensers are successively discharged one by one over the transmitter relay S by actuation of the contacts governed by the cam disks M1 to Me. The transmitter relay S therefore re-transmits the received impulses in a time-sequence which is determined by the syn-. chronous control. Inasmuch as the length of the individual current impulse is determined by the cam disks M1 to M5, the transmission obtained in this manner also effects correction of distortions of the signals.

In the embodiment shown in Fig. 3, reversal of the charge of the condenser C is effected by the operative actuation into alternate position of the armature e which corresponds to the armature e of the line relay E shown in Figs. 1 and 2. The release control magnet A thereby receives a momentary current impulse and releases the pawl K by actuation of its detent armature. The effect is thus exactly the same as in Figs. 1 and 2.

Fig. 4 shows an embodiment which operates similarly, but employs a transformer W. The switching over into alternate position of the armature e alters the current in the primary winding and thereby produces a current impulse in the secondary winding, which causes energization of the release control magnet A, causing attraction of its detent armature and thus resulting in the release of the pawl K.

In Fig. 5 is illustrated an example of the invention in which the operative release of the pawl K to release the cam shaft of the receivin distributor is effected only in response to the changeover of the signal current in the transmission line from spacing to marker current. The operation of the contact e responsive to change-over from marker to spacing current remains without effect. It is assumed that the line current (spacing current) affects the relay E normally in such a manner that the armature e is in the position shown, maintaining engagement with its left hand contact which is connected to +TB. If the receiver current is altered (marker current) to eilect op-- eration of the relay E so as to switch the armature into engagement with the right hand contact, the charge of the condenser C will be reversed. The current direction is now such that current flows through the winding of the release control magnet A, rectifier G1 and condenser C to TB, effectin energiaation of magnet A and therefor an operative release of the cam shaft. If the armature e is restored into engagement with its left hand contact, responsive to spacing current on the line, the current will iiow from +TB over the condenser C and rectifier G2 to ground. The rectifier G1 blocks the circuit to the release magnet A and the latter remains inoperative. The detent armature of the magnet A therefore will be in position for stopping coaction with the pawl K at the end of the code signals. Upon switching of the armature e to TB (marker current) the by-pass relay U will be energized over a normally closed contact controlled by the cam disk H, and upon energization actuates its contact 1:. The transmitter relay S will thereupon energize responsive to actuation of the contact associated with the cam disk J, in the normal or resting position of the transmit ting portion of the circuit, creating a condition in the relay 5, and line as, In corresponding to the condition then present in line a1, bi. It will be noted that this action is not in and of itself effective to release the transmitter cam shaft nor will a subsequent reversal of the armature e to +TB (spacing current) effect such a release. However, as the initial actuation of the armature e to TB (marker current) also energizes the release control magnet A, the pawl K will be released, permitting the receiver cam shaft to rotate. As cam disk H advances, the relay U is disconnected and control magnet B is energized when cam disk F closes the contacts associated therewith, thus releasing pawl L and permitting the transmitter cam shaft to rotate. Prior to the completion of one revolution of the receiver cam shaft, the cam disk F will open the circuit to control magnet B, permitting pawl L to resume its original position and stop the transmitter cam shaft upon its completion of one revolution. The release and stopping of the transmitter cam shaft thus is controlled by the receiver cam shaft and as the relay U is slow actuating and will tie-energize with a predetermined delay, the transmitted starting signal will be of suitable duration and properly timed with the subsequently transmitted marker and space impulses. However, the by-paes relay U, which is slow acting, will deenergize with a pre" determined delay, restoring its contact a into the position shown and thereby connecting current of opposite polarity to the transmitter relay S. The current alteration which occurs at the line relay E is thus effective to the transmitter relay without causing operative release of the transmitter cam shaft. The remaining parts of the arrangement, which are required for repeating the signals, are indicated by the cam disks N1, N2, M1, M2 and by the condensers Cl and C2.

The circuit shown in Fig. 5 also serves the purpose of repeating in the normal position of the receiver system the condition obtaining at the input :11, In to the output as, The by-pass relay U, being slow acting, does not energize responsive to momentary closure or the contact coact ing with the cam disk H; it responds operatively only to a prolonged impulse. It energizes or remains at rest, depending on the position of the armature e. After the transmitter shaft and therewith also the cam disl: J have arrived in normal position, the corresponding condition will be transmitted to the transmitter relay S and therewith to the output a2, 62, depending on the position of the armature u.

If the current on the line al, In is altered in a predetermined direction, the effect is generally opposite to that which results responsive to current alteration in the contrary direction. It may be desired or necessary, however, to produce such effect directly with respect to the release element. It is desirable, for example, in mag-= neticallyoperating arrangements, to avoid alteration of the magnetization device.

Fig. 6 shows how much a release control mag 7 ture e from one side to the other. control magnet A is connected in a rectifier bridge circuit comprising the rectifiers G1 to G4 and therefore always receives current impulses of the same direction.

An arrangement operating similarly for the control of an amplifier tube is shown in Fig. '7. The resistor W1 is shunted to ground whenever the armature e of the receiver relay (E in Figs. 1, 2 and 3) is in engagement with one or the other of its coacting contacts. At the grid of the tube R is the cathode potential. The shunt is removed from the resistor W1 during the interval of operative actuation of the armature e from one to the other of its coacting contacts. The negative potential connected with the resistor W2 becomes effective in this instance and alters the grid potential and therewith also the anode current.

Changes may be made within the scope and spirit of the appended claims.

We claim:

1. In a telegraph system having start-stop printer means and repeater apparatus in which a transmitter line terminates over which signals are received which include cyclically transmitted sets of code impulses comprising marker and spacing impulses and over which may be in addition transmitted prolonged current impulses signifying control signals, and having a line relay which is responsive to all said impulses, and having a code signal-receiving distributor for receiving said sets of marker and spacing impulses and transmitter means including a transmitter relay to which said received impulses are transmitted, a start-stop mechanism individual to said signal-receiving distributor, a release control magnet which forms part of said mechanism for releasing said receiving distributor for operation for predetermined periods coinciding with the periods of cyclic transmission of said marker and spacing impulses, circuit control means for causing the release operation of said release control magnet only at the instant coinciding with the change-over from a normal current condition on said line to a current condition signifying a start signal and for causing said release magnet to stop the operation of said distributor upon termination of each predetermined operating period irrespective of the presence of a prolonged current condition on said line which signifies a control signal, said circuit control means comprising a contact spring controlled by said line relay and connected with said release control magnet, a by-pass relay connected with said contact spring, contact means carrying predetermined potentials for connection with said contact spring in alternate positions thereof, and means governed by said bypass relay ior controlling said transmitter relay independent of the release of said signal-receiving distributor.

2. In a telegraph system having start-stop printer means and repeater apparatus in which a transmitter line terminates over which signals are received which include cyclically transmitted sets of different current conditions signifying code signal impulses and prolonged current impulses signifying control signals, respectively, and having a line relay which is responsive to said code signal impulses and to said prolonged current impulses, and having a code signal impulse-receiving distributor which includes a set of contacts, a start-stop mechanism individual to said set of contacts for actuating said con- The release tacts for the duration of predetermined cyclic periods so as to close such contacts in such periods in succession in accordance with sets of code signal impulses received during such periods, control means for effecting the operation of said mechanism for each cyclic period, said control means comprising a release control magnet having a winding, and circuit control means for governing said control means to release said mechanism for operation for each cyclic period only in response to change-over on said line of a current condition thereon which signifies a predetermined code signal impulse and for stopping said mechanism at the termination of each cyclic period of operation independent of any current condition on said line which signifies a prolonged current impulse, said circuit control means comprising said winding, rectifier means in series with said winding, capacitor means in series with said rectifier means, and a contact controlled by said line relay disposed in series with said capacitor means.

3. In a telegraph system having start-stop printer means and repeater apparatus in which a transmitter line terminates over which signals are received which include cyclically transmitted sets of different current conditions signifying code signal impulses and prolonged current impulses signifying control signals, respectively, and having a line relay which i responsive to said code signal impulses and to said prolonged current impulses, and having a code signal impulse-receiving distributor which includes a set of contacts, a start-stop mechanism individual to said set of contacts for actuating said contacts for the duration of predetermined cyclic periods so as to close such contacts in such periods in succession in accordance with sets of code signal impulses received during such periods, control means for effecting the operation of said mechanism for each cyclic period, current differentiating means for governing said control means to release said mechanism for operation for each cyclic period only at the instant of change-over,

on said line from one to another predetermined current condition thereon and for stopping said mechanism at the termination of each cyclic period of operation independent of any current condition on said line which signifies a prolonged current impulse, transmitter means for transmitting the sets of code signal impulses received by said receiving distributor, a transmitter relay for said transmitter means, a bypass relay coacting with said receiving distributor, and circuit means controlled by said by-pass relay for transmitting to said transmitter relay predetermined current conditions on said transmitter line independent of the release of said start-stop mechanism. 7

4. In a telegraph system having start-stop printer means and repeater apparatus in which a transmitter line terminates over which signals are received which include cyclically transmitted sets of different current ,conditions signifying code signal impulses and prolonged current impulses signifying control signals, respectively, and having a line relay which is responsive to said code signal impulses and to said prolonged current impulses, and having a code signal impulsereceiving distributor which includes a set of contacts, a start-stop mechanism individual to said set of contacts for actuating said contacts for the duration of predetermined cyclic periods so as to close such contacts in such periods in succession in accordance with sets or code signal impulses received during such periods, control means for effecting the operation of said mechanism for each cyclic period, said control means comprising a release control magnet having a winding, and circuit control means for overning said control means to release said mechanism for operation for each cyclic period only in response to change-over on said line of a current condition thereon which signifies a predetermined code signal impulse and for stopping said mechanism at the termination of each cyclic period of operation independent of any current condition on said line which signifies a prolonged current impulse, said circuit control means comprising said winding, capacitor means in series with said winding, a contact spring controlled by said line relay disposed in series with said capacitor means, and contacts carrying predetermined potentials for engagement by said contact spring in alternate positions thereof.

5. In a telegraph system having start-stop printer means and repeater apparatus in which a transmitter line terminates over which signals are received which include cyclically transmitted sets of diiferent current conditions signifying code signal impulses and prolonged current impulses signifying control signals, respectively, and having a line relay which is responsive to said code signal impulses and to said prolonged current impulses, and having a code signal impulse-- receiving distributor which includes a set of contacts, a start-stop mechanism individual to said set of contacts for actuating said contacts for the duration of predetermined cyclic periods so as to close such contacts in such periods in succession in accordance with sets of code signal impulses received during such periods, a release magnet having a winding for effecting the operation of said mechanism for each cyclic period, current differentiating means comprising a trans, former having its secondary winding in parallel with the winding of said release magnet for governing the actuation thereof to release said mechanism for operation for each cyclic period only at the instant of change-over on said line from one to another predetermined current con-- dition thereon and for stopping said mechanism at the termination of each cyclic period of operation independent of any current condition on said line which signifies a prolonged current impulse, a contact spring controlled by said line relay disposed in series with the primary winding of said transformer, and contacts carrying predetermined potentials for engagement by said contact spring in alternate positions thereof.

EHRHARD ROSSBERG. WILHELM LOCKEMANN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,006,582 Callahan July 2, 1935 2,373,970 Mathes Apr. 17, 1945 FOREIGN PATENTS Number Country Date 531,820 Great Britain Jan. 13, 1941 

